I have a knitting question about a crochet hook! If I'm just looking for a basic crochet hook for knitting purposes--such as fixing dropped stitches, making fringe for a scarf, etc.--what size or type would you recommend?

It depends on the gauge of your knit garment. I'd get one within a couple sizes of your needles, so check your needle gauge to see which is closest. You should be able to fudge a bit on sizes - just don't use a super-tiny hook to make a fringe from chunky yarn or a giant hook to pick up stitches for your lace sock!

Ditto on the gauge recommendation. I own both metal and plastic crochet hooks and both work great. Hobby Lobby puts all crochet hooks and knitting needles on for half price every three months or so. If you have one of those, you can pick up a set in a range of sizes for super-cheap. They also have a 40% off coupon every other week (which is almost as cheap).

Being able to do a single crochet edging, etc. can come in really handy with your knitting.

i think i have about 10 different hooks that i only use for fringe and for dropped stitches. i can fix both without but it is so much easier with. i don't know that i have a preference for materials but i do use the metal more...really just because they happen to be the sizes i am needing at the moment.

Hobby Lobby does have the coupon online this week. you can get a set of the Boye's hooks like the interchangeable knitting needle package that is fairly inexpensive, especially with the coupon.